SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ab63ce22999fe25a5f73bd62f5eeb031624da9002839ba0b71bde4294873635' 
  AND token = '/EaWs9HreRSHDSZfd0YFKmVugBti12YPMUefqcqyk70=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}